This application claims the priority of Korean Patent Application No. 2003-82348, filed on Nov. 19, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a data transceiver and method, and more particularly, a data transceiver and method for transceiving data performing equalization and pre-emphasis adaptive to transmission characteristics of a receiving part.
2. Description of the Related Art
A square wave transmission signal, such as a binary data signal, which includes both high-frequency components and low-frequency components, is widely used in wired digital communications. While the square wave transmission signal is passing through a transmission line, the high-frequency components are attenuated more than the low-frequency components, thus resulting in signal distortion. Thus, a timing margin required for perceiving input data without errors at a receiving terminal is reduced.
To solve this problem, an equalization method and a pre-emphasis method have been proposed. In the equalization method, the distorted waveform of a data signal is decoded at a receiving terminal. In the pre-emphasis method, the waveform of an input data signal is distorted at a transmitting terminal beforehand in consideration of a signal attenuation characteristic of a transmission line of a receiving part, so that the waveform of an output data signal remains optimized at a receiving terminal.
However, in these methods, if the equalization function of the receiving terminal and a parameter required for pre-emphasis at the transmitting terminal are controlled by external controllers, since the transmitting or receiving terminal should be controlled after manually measuring the signal attenuation characteristic of the transmission line, the efficiency is low. And the signal attenuation characteristic of the transmission line cannot be precisely measured with the transmitting and receiving terminal connected to the each side of the transmission line.
On the other hand, an equalization parameter may be automatically controlled through feedback operations at a receiving terminal, or a pre-emphasis parameter may be automatically controlled at a transmitting terminal by two transceivers that are disposed one at either end of a transmission line, perform the same functions, and transmit and receive test signals based on predefined rules. In these methods, the foregoing problems can be solved, but each transceiver should include additional devices that perform the automatic control functions. Thus, if a multiple link system comprised of a plurality of transceiving apparatuses is required, power consumption and cost are high. Also, pairs of transceivers should have the same functions.
Further, in conventional data transceiving methods, an equalization parameter or a pre-emphasis parameter, which is required to compensate for the signal attenuation characteristic of a transmission line, should be set in an initial operation of a transceiver. For this reason, the conventional methods should further include compensation functions for factors such as changes in temperature or characteristics of input and output buffers of transceiving terminals, which may affect the signal attenuation characteristic of the transmission line during operation of the transceiver.